Detect Box Pick Point

The coordinate frame of the box’s pick can be requested from a ros service that detects it by processing the sensor data. In this exercise, we will learn how to use a service client to call that ros service for the box pick pose.

Locate Function

  • In the main program, locate the function call to application.detect_box_pick().
  • Go to the source file of that function by clicking in any part of the function and pressing “F2”.
  • Remove the first line containing the following ROS_ERROR_STREAM ... so that the program runs.

Complete Code

  • Find every line that begins with the comment Fill Code: and read the description. Then, replace every instance of the comment ENTER CODE HERE with the appropriate line of code
/* Fill Code:
     .
     .
     .
*/
/* ========  ENTER CODE HERE ======== */
  • The target_recognition_client object in your programs can use the call() method to send a request to a ros service.
  • The ros service that receives the call will process the sensor data and return the pose for the box pick in the service structure member srv.response.target_pose.

Build Code and Run

  • Compile the pick and place node:
    • in QTCreator: Build -> Build Project
    • Alternatively, in a terminal:
catkin build --pkg collision_avoidance_pick_and_place
  • Run your node with the launch file:
roslaunch collision_avoidance_pick_and_place ur5_pick_and_place.launch
  • A blue box and voxel grid obstacles will be displayed in rviz. In the terminal you should see a message like the following:
[ INFO] [1400554224.057842127]: Move wait Succeeded
[ INFO] [1400554224.311158465]: Gripper opened
[ INFO] [1400554224.648747043]: target recognition succeeded
[ERROR] [1400554224.649055043]: create_pick_moves is not implemented yet.  Aborting.

API References

call()